Intermittent advancing device for a rotatable boring machine

ABSTRACT

Tool for a rotating head of a continuous boring or cutting machine, mounted on a tool-carrier fixed on the said rotating head and driven in a rotating sweeping movement in a plane passing through the axis of rotation of the said rotating head, performing regular work due to a discontinuous advance device, obtained by means linked to cylinders exerting a periodic thrust on the rotating head at each change in the direction of oscillation of the said tool-carrier.

United States Patent [191 Montacie June 4, 1974 INTERMI'ITENT ADVANCINGDEVICE FOR A ROTATABLE BORING MACHINE Marcel Montacie, Paris, Francealie eak iqs fi fls flmr na Paris, France Filed: May 8, 1972 Appl. No.:251,141

Related [15. Application Data Continuation-in-part of Serv No. 152,839.June 14., 1971, Pat. No. 3,773,387. which is a continuation-in-part of-Ser. No. 848,013 Aug. 6, i969, abandoned.

Inventor:

Assignee:

Foreign Application Priority Data May 7,1971 France 71.16654 [1.8. CI.299/61 Int. Cl. v. EOlg 3/04 Field of Search 299/31, 85, 86, 6]

References Cited UNITED STATES PATENTS v Starr et al 299/3l X 6/l968Hoever 299/86 X FOREIGN PATENTS OR APPLICATIONS 1,938,8l8 2/l970 Germany299/86 Primary Examiner-Ernest R. Purser Attorney, Agent, orFirm-Sughrue, Rothwell, Mion, Zinn & Macpeak 5 7 ABSTRACT Tool for arotating head of a continuous boring or cutting machine, mounted on atool-carrier fixed on the said rotating head and driven in a rotatingsweeping movement-in a plane passing through the axis of rotation'of thesaid rotating head, performing regular work due to a discontinuousadvance device, obtained by means linked'to cylinders exerting aperiodic thrust on the rotating head at each change in the direction ofoscillation of the said tool-carrier.

10 Claims, 3 Drawing Figures PATENTEDJuu 4:914

sum 1 or 3 FIG/B PATENTEDJuu 4 I974 sum 2 0F 3 FIGQ PATENTEDJUN 41974 11 483 sum 3 or 3 1 INTERMI'ITENT ADVANCING DEVICE FOR A ROTATABLE BORINGMACHINE CROSS REFERENCES TO RELATED APPLICA- TIONS This application is acontinuation-impart of copending application Ser. No. l52,839, filedJune l4, l97l, which has subsequently matured into Pat. No. 3,773,387,issued Nov. 20, I973. Application Ser. No. l52,839 was in turn acontinuation-in-part of copending application Ser. No. 848,013, filedAug. 6, I969, and now abandoned.

The present invention relates to discontinuous advance devices as muchfor making continuous operation of the oscillating tools of a continuousboring or cutting machine easier as for making the regularity of theoscillating movement of the various tool-carriers and the synchronisingof the said movements together easier.

Indeed, it is known that the thrust effort on a tool determines thedepth to which the latter drives into the ground or the rock of theworking face and the said driving in turn determines the resistancetorque applied to the cutting head by the said tool.

The operating method used up till now consisted in exerting a continuousthrust on the boring head effecting a progressive driving in of thetools giving rise to peak resistance torques incompatible with theregular operation of the machine.

One of the objects of the present invention is to effect constantdriving in of the tool enabling operation at a constant torque by theaction of a then regular thrust. To do this, the advancing of themachine is effected in jerks at the end of each oscillation of thetool-carriers,

- as much towards the outside as towards the inside, that is, at themoment of the change in direction of the movement and, of course, toobtain that result, the tools mounted on the said rotating head mustarrive at the end of their stroke at the same time, that is, they mustbe synchronised. the ones being in the position close to the axis ofrotation of the said head, the others in the position furthesttherefrom, so as to counterbalance the torques caused by the varioustools as well as possible.

Lastly, the control device for reversing the movement of thetool-carriers, using end-of-stroke switches exposed at the front of therotating head, gives rises to irregularities in operation connected withthe risks resulting from the changing conditions of the ground,

. during operation to overcome these uncertainties, and

to simplify the control device for reversing the oscillating movement ofthe tool-carriers: on the one hand, the drive jacks for oscillation ofthe tool-carriers are supplied with fluid through a rotating connectionenabling the use of a fixed control device placed in safety behind themachine, and on the other hand, reversing control is effected by atime-switch ensuring a given periodicity of the movements andindependent from oscillation variations of the tool-carriers about theiraverage value.

The present invention has for its object a tool for a rotating head of acontinuous boring or cutting machine, mounted on a tool-carrier fixed tothe said rotating head and driven with a rotational sweeping movement ina plane passing through the axis of rotation of the latter and on whichmeans connected with thrust jacks exert periodic efforts producing adiscontinuous advance of the said tool at each change in the directionof the oscillating movement of the said tool-carrier.

The aims and other advantages of the present invention will becomeapparent from the following description, which has no limitingcharacter, of an example of an embodiment, with reference to thedrawings in which:

FIG. 1 shows a boring head assembly with oscillating tool-carriers and afixed hydraulic control system, acting through a rotating connection,

FIG. 2 shows the hydraulic diagramme of the sweeping device of atool-carrier,

FIG. 3 shows hydraulic diagramme of the device for advancing by jerks orfor controlling the thrust.

FIG. 1, the boring head I driven in a rotatingmovement in the directionshown by the arrow 2, by the shaft 3 on which it is fixed, is fittedwith tools of the cutter wheel type 4, rotating on shafts 5 mounted ontoolcarriers 6 oscillating on shafts 7 mounted on supports 8 fixed tothe said head 1.

Cylinders 9 mounted for oscillation on trunions 10 drive thetool-carriers 6 in an oscillating movement by means of the rods 11 fastwith the positions of the said cylinders 9; whereas a shaft 12 rotatingin the toolcarrier 6 and crossed by the end of the rod 11 ensures therequired fixing between the said rod 11 and the tool-carrier 6.

The rods 9 are connected to a fixed hydraulic control assembly 13,through a rotating connection 14 whose fixed part 15 is connected byfixed tubes 16 to the assembly 13 and whose rotating part 17 receivestubes 18 mounted on the rotating head I and connected to the jackcylinders 9, each of the tubes 18 being connected to the correspondingtube 16 to constitute the hydraulic circuit of the individual controldevices for the jack cylinders 9.

The axes of the shafts 7 on which the tool-carriers 6 oscillate areperpendicular in space to the axis of rotation of the shaft 3 bearingthe rotating head 1 and situated, in space, at an equal distance fromthe latter. Likewise, the shafts 10 and 12 are perpendicular to theshaft 3 and the plane of symmetry of the tool-carriers 6 pass constantlyduring the oscillation of the latter through the axis of rotation of theshaft 3 and contains the rotation axis of the shaft 5 on which the tool4 turns freely.

The tunnel 19 which has a toroidal working face 2 0 is cut away by fourtools 4 each arranged so as to from a spiral cut in the respectivesections 20a, 20b, 20c and 20d, swept by them during their oscillation,whereas when there is no oscillation, the tools each form a circular cutas is known in machines where the tools are mounted fixed directly tothe front of the rotating head.

The tool at the top of FIG. 1 follows the section 20a and the tool atthe bottom follows the section 20b, each of these being shown in itspositionfurthest from the axis, that is, at the moment when theoscillating direction changes.

Turning to FIG. 2, cylinder 9 is connected with its hydraulic controlcircuit, whose hydraulic oil, arriving through the tubes 16, passes inthe tubes 18 after having crossed the rotating connection 14. It is adouble acting jack cylinder in which the rod 11 of the piston 21 ensuresthe oscillating movement of the corresponding tool carrier 6, which isnot shown. Each jack cylinder 9 is connected up to a pump having twobodies 22 and 23 respectively whose cylinders correspond to the unequalvolumes of the chambers 24 and 25 respectively, the diflerence betweenthe said two volumes being due to the rod 11 which moves in the chamber24.

The shaft 26 of the double pump is, to great advantage, driven in arotating movement in the direction of the arrow 27 by an independentelectric motor, it being possible for one and the same electric motor todrive all the pumps of the various tool-carriers. It is evident that thedouble pump could be driven mechanically by the rotating of the head.

Distributors 28 having four channels, which are electrically operated bya winding 28a, are installed between the pumps and the jack cylinders tocontrol the oil flow direction in the hydraulic circuit; thus, in FIG.2, the rod 11 enters the jack cylinder 9 in the direction of the arrow29 to move the corresponding tool away from the axis of the rotatinghead, under theeffect of the oil coming from the pump body 22, flowingthrough the distributor 28 in the direction of the arrow 30 and flowingin the tube 16 in the direction of the arrow 31, whereas the oil comesfrom an oil tank 32 subjected to a pressure in the order of one bar,passing as much through the central tube 33, through the non-returnvalve 34, as through the tube 35 and the distributor 28; appropriatearrows show the oil flow direction. Other non-return valves andpressure, limiters 36 complete the hydraulic circuit, whereas the tubes33a shown in dotted lines are used for the scavenging of leakage oil.When the flow direction is reversed, the distributors 28 ensure thecrossing of the hydraulic circuits symbolised by the oblique straightlines 37 marked with arrows at their ends to show the new flowdirection. By this regulating of the pump discharge, the theoreticaltime of an outgoing or return stroke of the piston 21 of the jackcylinder 9 is regulated at a value T. By means of a time-switch device,the simultaneous reversing of the distributors 28 of the tool-carrierassembly 6 is affected at intervals of time To T+ I, I being a veryshort time in relation to T (in the order of 1 second) which enables thesynchronisation of the oscillating of all the tool-carriers to beensured, the rods 11 being blocked duringthe time t, by means of thepistons 21 abutting against one of the rings 38, whereas the pumpsdischarge at that instant through their pressure limiters 3.6.

The time-switch device controls the reversing of the distributors 28 bymeans of a contact switch equipped with one contact per tool-carrier6 tobe controlled, the contact switch being of .the open or closed type; inthese conditions, each contact controls respectively the de-energisingand supplying of the windings 28a of the distributors28 assigned to thehydraulic control circuit of a same tool-carrier 6 so as to select theoscillating direction of the tool-carriers, the ones moving closer tothe axis of rotation of the head in the direction of the arrows 39a and39b, the others moving away from it in the direction of 390 and 39d, asshown in FIG. 1. Actually, it is absolutely essential for the furthestsections a and 20b to be covered simultaneously in the same direction inrelation to the axis of rotation of the rotating head.

Numerous variations of this hydraulic configuration are possible. Thus,double pumps with axial pistons can be used, and the reversing of theoil flow is effected by reversing the plate of the said pump, In thecase where constant, taking into account the inertia of the as'semblyand the drive method by a redundant power motor.

The average oscillating frequency of the tool-carriers is alsodetermined during manufacturing and in relation to the angular rotatingspeed of the head so as to make the tool form a cut having a spiralshape of given medium pitch on the working face whereas to take intoaccount the variousworking parameters, more particularly the hardness ofthe rocks on the ground to be bored, the saidpitch can be adapted to thework required, by modifying the discharge of the control pumps of thejack cylinders 9, but the maintaining of that pitch,. that is, of theratio between the rotating speed of the head and the sweeping speed ofthe tool ,carriers is not critical, for therotating speed beingpractically constant, and the sweeping speed being adjustable, a strictsynchronising of these two movements is useless, and thus, they can beobtained by independentdrive means. I

Turning to FIG. 3, a hydraulic pump 40 having an adjustable discharge of0 litres par second is driven in a rotating movement in the direction ofthe arrow 41 by an electric drive motor 42 and discharges into ahydraulic accumulator 43- whose inflation pressure is greater than thatnecessary for making the boring machine advance. A single hydraulicdistributor 45 electrically controlled by a winding 45a and normallyclosed is mounted between the accumulator 43 and the thrust jackcylinders 44.

The jack cylinders 44 are mounted between the mobile structuresupporting the rotating headl of the machine and the support points ofthe latter on the ground to be drilled so as to exert, on the said head,the required thrust.

At each reversing 'of the oscillating direction of the tool-carriers,the time-switch device for controlling the reversing of the tool-carrieroscillating direction by the four-channel electrodistributors 28 alsocontrols, by means of time-delay relays, the opening'of the singleelectrodistributor 45 during a time which is adjustable between two andfour seconds, enabling all of the oil stored in the accumulator 43 topass into the jack cylinders 44, ensuring advancing in jerks.

Thus, at each reversing or backing away of the toolcarriers, the machineadvances a certain distance connected simultaneously with the durationtime T of a half-oscillation of the tool-carriers and with theadjustable discharge Q of the pump 40.

In the case of a cutting machine, the thrust on the rotating head isproduced by means of the tracks on which the machine is mounted, theselatter being driven by a hydraulic motor and the advancing by jerks ofthe said machine is then obtained by supplying the said hydraulic motorwith oil from the accumulator 43 during the required discharging time ofthe latter.

This hydraulic advances control system is equipped with a general oiltank 46 at which the various oil circuits of the device, equipped,moreover, with pressure limiters 47 and 48, non-retum valves 49 and 50,end stop cocks 51 used for isolating the accumulator 43.

What is claimed is: is:

l. A discontinuous advancing device for a continuous boring or cuttingmachine having a continuously rotatable head and tool means mounted foroscillation on said head for movement in a rotating sweeping movement ina plane passing through the axis of rotation of said rotatable head,comprising thrust jack cylinder means mounted on said machine inengagement with said head and hydraulic means for periodically operatingsaid cylinder means for exerting a thrust on said head at each change inthe oscillating direction of said tool means.

2. A discontinuous advancing device according to claim 1 wherein saidhydraulic means comprises a hydraulic accumulator, conduit means,connecting said accumulator to said cylinder means and electricallyoperated valve means for periodically controlling the discharge of saidaccumulator into said thrust jack cylinder means.

3. A discontinuous advancing device according to claim 1 wherein saidhydraulic means comprises a hydro-pneumatic pressure multiplier, conduitmeans connecting said multiplier to said cylinder means includingelectrically operated valve means for controlling the thrust jackcylinder means.

4. A discontinuous advancing device accordingto claim 1 and furthercomprising double acting hydraulic cylinder means for oscillating saidtool means, a fixed hydraulic control device, rotating connection meansconnecting said control device to said double acting hydraulic cylindermeans, said control device comprising a pump, hydraulicelectro-distributor inverter means for controlling said double actinghydraulic cylinder means, switch means, and circuit means including saidswitch means for controlling the operation of said double actinghydraulic cylinder means.

5. A discontinuous advancing device according to claim 4 wherein saidhydraulic means comprises a hydraulic accumulator, conduit meansconnecting said accumulator to said thrust jack cylinder means, andelectrically operated valve means for periodically controlling thedischarge of saidaccumulator into said thrust jack cylinder means; and

- wherein said switch means simultaneously controls said hydraulicelectro-distributor inverter means to control the oscillating movementof said tool means and said electrically operated valve means forperiodically controlling the discharge of said accumulator intosaid-jack cylinder means.

6. In a continuous drilling or boring machine having a boring headrotatable about an axis and at least one cutting tool mounted on a toolholder for oscillatory sweeping movement in a plane passing through theaxis of rotation of said boring head, the improvement comprising:

means having a thrust jack for exerting a periodic thrust to effect adiscontinuous advance of the tool upon each change in direction ofoscillation of the tool holder.

7. A machine according to claim 6, wherein the discontinuous advance iseffected by a hydraulic accumulator associated with an electric controlcock and discharging periodically in the thrust jack.

8. A machine according to claim 6, wherein the discontinuous advance isprovided by a hydro-pneumatic pressure multiplier associated with anelectric control cock placed in the supply circuit for the thrust jack.

9. A machine according to claim 6 comprising a plurality 'of cuttingtools mounted on oscillatable tool holders; and wherein each of the toolholders is oscillated by a double-action hydraulic jack acting on thetool holder, at fixed hydraulic control device is connected to each jackthrough a turning joint; a pump is connected to each jack and theturning joint through a hydraulic inverter electro-distributor; andmeans is provided for synchronizing the movement of the tool holders,said synchronizing means comprising a timer periodically energizing thecoil of a contactor having supply contacts for the excitation coils ofthe distributors, and mechanical stops arranged in the jacks.

10. A machine according to claim 9 wherein an excitation coil of anelectric cock controls the periodic advance of said boring head, and thetimer that controls the electro-distributors simultaneously ensures theshort-duration supply of said cock coil through timed contact therewith.

1. A discontinuous advancing device for a continuous boring or cuttingmachine having a continuously rotatable head and tool means mounted foroscillation on said head for movement in a rotating sweeping movement ina plane passing through the axis of rotation of said rotatable head,comprising thrust jack cylinder means mounted on said machine inengagement with said head and hydraulic means for periodically operatingsaid cylinder means for exerting a thrust on said head at each change inthe oscillating direction of said tool means.
 2. A discontinuousadvancing device according to claim 1 wherein said hydraulic meanscomprises a hydraulic accumulator, conduit means, connecting saidaccumulator to said cylinder means and electrically operated valve meansfor periodically controlling the discharge of said accumulator into saidthrust jack cylinder means.
 3. A discontinuous advancing deviceaccording to claim 1 wherein said hydraulic means comprises ahydro-pneumatic pressure multiplier, conduit means connecting saidmultiplier to said cylinder means including electrically operated valvemeaNs for controlling the thrust jack cylinder means.
 4. A discontinuousadvancing device according to claim 1 and further comprising doubleacting hydraulic cylinder means for oscillating said tool means, a fixedhydraulic control device, rotating connection means connecting saidcontrol device to said double acting hydraulic cylinder means, saidcontrol device comprising a pump, hydraulic electro-distributor invertermeans for controlling said double acting hydraulic cylinder means,switch means, and circuit means including said switch means forcontrolling the operation of said double acting hydraulic cylindermeans.
 5. A discontinuous advancing device according to claim 4 whereinsaid hydraulic means comprises a hydraulic accumulator, conduit meansconnecting said accumulator to said thrust jack cylinder means, andelectrically operated valve means for periodically controlling thedischarge of said accumulator into said thrust jack cylinder means; andwherein said switch means simultaneously controls said hydraulicelectro-distributor inverter means to control the oscillating movementof said tool means and said electrically operated valve means forperiodically controlling the discharge of said accumulator into saidjack cylinder means.
 6. In a continuous drilling or boring machinehaving a boring head rotatable about an axis and at least one cuttingtool mounted on a tool holder for oscillatory sweeping movement in aplane passing through the axis of rotation of said boring head, theimprovement comprising: means having a thrust jack for exerting aperiodic thrust to effect a discontinuous advance of the tool upon eachchange in direction of oscillation of the tool holder.
 7. A machineaccording to claim 6, wherein the discontinuous advance is effected by ahydraulic accumulator associated with an electric control cock anddischarging periodically in the thrust jack.
 8. A machine according toclaim 6, wherein the discontinuous advance is provided by ahydro-pneumatic pressure multiplier associated with an electric controlcock placed in the supply circuit for the thrust jack.
 9. A machineaccording to claim 6 comprising a plurality of cutting tools mounted onoscillatable tool holders; and wherein each of the tool holders isoscillated by a double-action hydraulic jack acting on the tool holder,a fixed hydraulic control device is connected to each jack through aturning joint; a pump is connected to each jack and the turning jointthrough a hydraulic inverter electro-distributor; and means is providedfor synchronizing the movement of the tool holders, said synchronizingmeans comprising a timer periodically energizing the coil of a contactorhaving supply contacts for the excitation coils of the distributors, andmechanical stops arranged in the jacks.
 10. A machine according to claim9 wherein an excitation coil of an electric cock controls the periodicadvance of said boring head, and the timer that controls theelectro-distributors simultaneously ensures the short-duration supply ofsaid cock coil through timed contact therewith.